When changing workspace, you can add your old SQL Project to the new workspace by right clicking in the SQL Project tab choose, "new" uncheck "use default location" browse to the directory of your old workspace/SQLproject

The datasource explorer caches definitions for table, view, user etc. The definitions are used to proof read SQL and mark missing objects. If a new object has been created, outside of DB Optimizer, since it's been running, then it will be missing from the cache and flagged as non-existent in the SQL Editor. This can be fixed by refreshing the cache:

Window -> Preferences -> SQL Development - > Data source Indexing -> Start IndexingNOTE: only objects checked inWindow -> Preferences -> SQL Development - > Data source Indexing will ever be refreshedNOTE: when ever DDL is run inside of DBO, the cache will be refreshed automatically to reflect any changes if running DDL from some other tool, the DBO won't know to sync it's cache

You can manually refresh a node in the data source explorer (for example to refresh tables only)

Right click on the table node in data source explorer , choose "refresh"

You can clear Data Cache to improve performance after running a long time and there is alot of cache from multiple datasources.Window -> Preferences -> SQL Development - > Data source Indexing -> Clear Index

Profiler:

NOTE:

Can only profile one data source at at time, though tuning can be run concurrently. (though you can start up a second DB Optimizer using a different workspace and profile a second data source)Profiler .oar files are not compatible between 1.0 and 1.5. In order to read both types, 1.0 and 1.5, both versions of DBO must be installed.Profiler .oar files can only be open with same version of database up to the two major numbers like Oracle 10.2 OAR can't be open with Oracle 10.1